Drop down NOT drag-drop exercise: (tab to the drop-down list, press Alt + down arrow to expand it, then use the arrow key to make the selection and Enter to accept it).
Pop up: error message maybe a warning only
Mark up any quotations with the Q and BLOCKQUOTE elements
<= => on buttons: use this instead: “Next exercise" and "Back".
XHTML validation: do not type simple HTML4 codes in caps, such as <B></B>
Bobby tests static web pages and cannot test HP pages correctly
Alt tags for images
Multiple-choice: it's perfectly legitimate to hide the
feedback for multiple-choice answers until the user chooses the answer, for instance is hidden.
Hot Potatoes 508 Compliance List